ADHD and Chronic Anhedonia: Antecedents of Treatment-Resistant Depression and Suicidality in Adults

Depression is a chronic and debilitating disorder. Approximately 280 million people live with depression, and more than 700,000 lives are lost due to suicide each year. Treatment-resistant depression (TRD) is a severe form of depression which is highly correlated with comorbid psychiatric disorders such as attention deficit hyperactive disorder (ADHD) and associated with increased suicidality. Anhedonia, the reduced ability to experience pleasure, is associated with various psychiatric conditions, including ADHD. The theoretical framework for this study was the biopsychosocial model. Depression may be diagnosed in accordance with a defined cluster of symptoms, and/or how symptoms are experienced vary by individuals is dependent on biological, psychological, social, and cultural influences, which may in turn influence response to treatment and predict a diagnosis of TRD and risk of suicidal behaviors. This study was a retrospective cross-sectional quantitative study that used archival data from a large tertiary psychiatric clinic based in Toronto, Ontario, Canada. Logistic regression was used to examine whether ADHD and chronic anhedonia alone or in combination predict treatment resistance and suicidality among depressed adults who are referred for psychiatric consultation. Results from this study demonstrate previously undiagnosed/untreated ADHD and chronic anhedonia were significant antecedents to the development of treatment resistance and suicidality in adults with depression. Positive social change may result by clinicians considering ADHD and chronic anhedonia as key risk factors for TRD and suicidality in this population and prioritize its assessment and management.